Portable hip-abducting seat support and method

ABSTRACT

A portable hip abduction apparatus for improving the posture and torso stability of a seated user, especially an individual with cerebral palsy. A flexible sheet is provided for placement on a seating surface. A backrest of the seating section and/or an incline block may be used to gradually elevate a seating section of the flexible sheet located adjacent a pommel attachment section. Along the pommel attachment section of the flexible sheet, a preferably trapezoidal abduction pommel is releasably connected. Due to the incline produced by either the incline block and/or the backrest, a user seated on the seating surface is urged towards the abduction pommel to wedge the user therebetween. In this manner, the wedging action causes the user&#39;s legs and hips to be abducted and the user&#39;s pelvis to be rotated forward toward vertical.

BACKGROUND OF THE INVENTION

[0001] The field of the invention generally pertains to orthopedic therapy devices. The invention relates more particularly to a portable hip-abducting seat support apparatus and method which wedges the user's pelvic region between an abduction pommel and an inclining surface to effect posture-correcting hip abduction when seated on virtually any type of seat surface, not limited to a wheelchair.

[0002] It is appreciated that cerebral palsy (CP) is a debilitating neuromuscular disorder which affects the control of muscles. In particular, many patients with CP have difficulty sitting upright in a seated position, whether it is sitting on a wheelchair with a backrest, or on a generally level surface such as the floor. Spastic or hypertonic conditions of the lower limbs often cause adduction and internal rotation of the lower limbs whereby the patient usually sits in a cross-legged position. This disorder can induce posterior rotation of the pelvis to compromise pelvic stability and adversely affect proper posture and torso control of the CP patient. Consequently, the hips may exhibit a tendency to slide forward when seated on a chair, and if not properly restrained, can result in the CP patient sliding off the chair and sustaining injuries.

[0003] It is known in the orthopedic and bio-mechanical disciplines that symmetrical hip abduction promotes and is an important condition for pelvic stability and proper posture when seated. Hip abduction provides a wider, more stable support for the upper body by enabling equal weight bearing and pressure distribution through both ischial tuberosities and thighs. Furthermore, hip abduction operates to induce anterior pelvic rotation such that the pelvis is brought into vertical alignment with the spinal column. In this regard, hip abduction can enable especially infants and small children to sit without using their hands for balance or support. Thus the infant or child may then be able to concentrate on other activities with less effort.

[0004] Various types of orthotic and orthopedic therapy devices, aids, and methods have been developed to promote hip abduction, especially when in a seated position. In particular, one common and widely used hip abduction aid is the abduction pommel, which is a simple device placed between the thighs to open and separate the legs. For example, two similar abduction pommel devices are disclosed in U.S. Pat. Nos. 5,127,709 and 5,758,926. In both cases, the abduction pommel is designed for use with a specially designed chair, i.e. a wheelchair ('709) or an adjustable seating system ('926). As shown, the abduction pommels are typically removable from the seat to enable easy access and exit of the patient. Morever, in both the '709 and '926 patents, the abduction pommels are placed at the front end of the seat to obstruct forward movement of a seated CP patient. This restraint-by-obstruction function is also illustrated in U.S. Pat. No. 5,551,107 for a modular cushion construction for use with a wheelchair. The modular cushion construction has a shaped foam base having a removable and contoured pommel portion. While not as tall as the block-configurations of the '709 and '926 patents, the removable pommel portion also helps to keep a user from sliding off the wheelchair seat.

[0005] Unfortunately, however, the utility of such abduction pommels is often severely limited by their exclusive association and use with wheelchairs. As can be seen from the representative examples, abduction pommels in the prior art have often been used as integrated features of wheelchairs, and are typically not operable apart from and independent of the associated wheelchair. This can severely restrict the seating options for CP patients when visiting various establishments and settings, as well as within one's home. Consequently, CP patients may be constructively confined to their wheelchairs during waking hours for lack of an alternative seating arrangement which provides similar support and safety features.

[0006] Furthermore, the representative prior art abduction pommels shown in the '709, '926 and '107 patents may not adequately induce anterior pelvic rotation to ensure pelvic stabilization and proper posture, simply by being interposed between the CP patient's legs. It is believed that pelvic stabilization may be best ensured by direct manipulation of the pelvic region to achieve and maintain a sufficient degree of hip abduction and pelvic rotation in the anterior direction. In the aforementioned patents, however, the abduction pommels do not necessarily come in contact with or abut against the pelvic region of a seated user until a time when the CP patient begins to slide forward. For example, as can be seen in FIG. 1 of the '709 patent the abduction pommel is positioned near the front edge of the seat far removed from backrest. While this may be suitable for blocking the user's pelvis from sliding off the front end of the seat, it may not prevent such sliding from occurring in the first place.

[0007] In summary, therefore, while it is known that hip abduction helps to improve the posture of a cerebral palsy patient, there is still a need to provide an abduction apparatus which effects hip abduction, anterior pelvic rotation/tilt, and proper posture by directly manipulating and stabilizing the pelvic region. Moreover, a simple, lightweight and portable abduction pommel apparatus would enable a CP patient to realize the benefits of such direct pelvic stabilization on virtually any seat, not limited to a wheelchair or other specially adapted chair. It is believed that such an apparatus may help initiate a process in which CP patients, especially infants and young children, learn how to overcome pathological patterns of movement. Moreover, a portable device would give CP patients some freedom to choose from a variety of seating arrangements and settings to make the endeavor a little more enjoyable and rewarding.

BRIEF SUMMARY OF THE INVENTION

[0008] It is an object of the present invention to provide a lightweight and portable hip abduction apparatus which may be used on virtually any seat having a base and a backrest, not limited to a wheelchair.

[0009] It is a further object of the present invention to provide a lightweight and portable hip abduction apparatus which may be used on virtually any generally level surface without a backrest, such as when seated on the floor.

[0010] A still further object of the present invention is to provide a portable hip abduction apparatus which, by direct contact and manipulation of the user's pelvic region, abducts the legs and hips of a seated user and rotates the pelvis in an anterior direction to improve pelvic and torso stability, and ensure proper posture.

[0011] Another object of the present invention is to provide a portable hip abduction apparatus having a flexible sheet component which enables the apparatus to substantially conform to the contact surface of a seat.

[0012] Another object of the present invention is to provide a portable hip abduction apparatus which directly contacts and manipulates a user's pelvic region for hip abduction by wedging the user between an abduction pommel and an incline surface.

[0013] Another object of the present invention is to provide a portable hip abduction apparatus having a flexible sheet construction with a friction-inducing bottom surface, wherein the friction-inducing bottom surface restrains the hip abduction apparatus from slipping when placed on a seat, with the slip-restraining action enabling the user's pelvic region to be wedged between a pommel block and an incline surface.

[0014] Another object of the present invention is to provide a portable hip abduction apparatus which utilizes the user's weight to wedge the user between an abduction pommel and an incline surface.

[0015] Another object of the present invention is to provide a simple, lightweight, and portable hip abduction apparatus for easy-carry portability, and having a minimum number of parts which are easily manufactured by conventional manufacturing methods.

[0016] Another object of the present invention is to provide a simple and efficient method for abducting the hips of a user by wedging the user between an abduction pommel and an incline surface, whereby the abduction pommel directly contacts and manipulates the user's pelvic region.

[0017] Another object of the present invention is to provide a method which utilizes the user's weight to wedge the user between an abduction pommel and an incline surface, with the wedging action operating to abduct the hips.

[0018] The present invention is for a portable hip abduction apparatus for improving the posture of a user, especially a user with cerebral palsy, when the user sits on a seat. It is appreciated that while the posture-correcting benefits to be gained from use of the hip abduction apparatus may be realized by any user, it is particularly useful when utilized by cerebral palsy patients, or someone with a debilitating muscular dysfunction who lacks substantial motor control and requires a wheelchair to move about. The portability of the hip abduction apparatus is designed to enable such a user to utilize the hip abduction apparatus with practically any seat surface encountered, in order that the user may be seated on the seat surface without the fear of sliding or falling out of the seat.

[0019] In a first preferred embodiment of the present invention, the hip abduction apparatus is used with a seat having a base and a backrest, and has a flexible sheet with a pommel section, a back section, and a seating section between the pommel section and the back section. Each of the sections have a top surface and a friction-inducing bottom surface. The apparatus also has an abduction pommel which is used to abduct the legs and hips of a user, and means for connecting the abduction pommel to the top surface of the pommel section of the flexible sheet. Placement of the abduction pommel in this manner allows a user seated on the top surface of the seating section to straddle the abduction pommel. With this configuration, the apparatus may be positioned on the seat such that the friction-inducing bottom surface of the pommel section contacts the base and the friction-inducing bottom surface of the back section contacts the backrest. The user may subsequently be straddle-seated on the flexible sheet to exert a distributive force against the top surfaces of the flexible sheet. Consequently, the friction-inducing bottom surfaces of the flexible sheet operate to restrain the flexible sheet from slipping on the seat so that the user may be wedged between the abduction pommel and backrest by the user's weight, and the wedging action causes the abduction pommel to abduct the user's legs and hips.

[0020] In a second preferred embodiment, the portable hip abduction apparatus is used with a generally horizontal surface, and comprises a flexible sheet having a pommel section and a seating section adjacent the pommel section. Each of the sections has a top surface and a friction-inducing bottom surface. Furthermore, the apparatus includes an abduction pommel for abducting the legs and hips of a user, and means for connecting the abduction pommel to the top surface of the pommel section of the flexible sheet. With this arrangement, a user seated on the top surface of the seating section may straddle the abduction pommel. Furthermore, the apparatus also includes an incline block for progressively elevating the seating section as distance from the pommel section increases. Construction of the incline block includes a lower surface for contacting the generally horizontal surface, and an incline surface which slopes upward from a lower edge to an upper edge above the lower surface. The incline surface operates to contact the friction-inducing bottom surface of at least the seating section of the flexible sheet with the upper edge of the incline block spaced a greater distance from the pommel section than the lower edge. With this configuration, the hip abduction apparatus may be positioned on the generally horizontal surface with the incline block placed between the generally horizontal surface and at least the seating section of the flexible sheet. The user may be subsequently straddle-seated on the flexible sheet to exert a distributive force against the top surfaces of the flexible sheet. In this manner, the friction-inducing bottom surfaces of the flexible sheet restrain the flexible sheet from slipping on the incline block such that the user is wedged between the abduction pommel and the incline block by the user's weight. And the wedging action causes the abduction pommel to abduct the user's legs and hips.

[0021] Additionally, the present invention is also for a method for abducting the hips of a user, especially a user with cerebral palsy, for improving the posture of the user when sitting on a seat with a base and a backrest. The method comprises the following steps:

[0022] First, a hip abduction apparatus as described above is provided having a flexible sheet with a pommel section, a back section, and a seating section between the pommel section and the back section. Each of the sections has a top surface and a friction-inducing bottom surface. The hip abduction apparatus also has an abduction pommel for abducting the legs and hips of a user, and means for connecting the abduction pommel to the top surface of the pommel section of the flexible sheet such that a user seated on the top surface of the seating section may straddle the abduction pommel.

[0023] The hip abduction apparatus is then positioned on the seat such that the friction-inducing bottom surface of the pommel section contacts the base, and the friction-inducing bottom surface of the back section contacts the backrest.

[0024] Next, a user is seated on the flexible sheet to straddle the abduction pommel and thereby exert a distributed load against the top surfaces of the flexible sheet.

[0025] The flexible sheet is then restrained from slipping on the seat by action of the friction-inducing bottom surfaces of the flexible sheet.

[0026] And finally, the user is wedged between the abduction pommel and the backrest by the user's weight such that the wedging action causes the abduction pommel to abduct the user's legs and hips. In a preferred embodiment, the back section of the flexible sheet is pulled upward while the user is seated, to draw in the abduction pommel closer to the backrest of the seat, and thereby further abduct the user's legs and hips.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027]FIG. 1 is a plan view of a first preferred embodiment of the portable hip abduction apparatus.

[0028]FIG. 2 is an elevational side view taken along line 2-2 of FIG. 1.

[0029]FIG. 3 is a front perspective view of the first preferred embodiment of the portable hip abduction apparatus which is positioned on a seat having a base and backrest.

[0030]FIG. 4 is a front perspective view of the first preferred embodiment of the portable hip abduction apparatus similar to FIG. 3, with a child/infant seated thereon.

[0031]FIG. 5 is an elevational side view taken along line 5-5 of

[0032]FIG. 4, and illustrating the operation of the first preferred embodiment of the portable hip abduction apparatus to wedge the child/infant between the abduction pommel and the backrest.

[0033]FIG. 6 is a general perspective view of the incline block.

[0034]FIG. 7 is a side elevational view similar to FIG. 5, wherein the hip abduction apparatus includes the use of the incline block to wedge the child/infant between the abduction pommel and the incline block.

[0035]FIG. 8 is a plan view of a second preferred embodiment of the portable hip abduction apparatus.

[0036]FIG. 9 is a front perspective view of the second preferred embodiment of the portable hip abduction when positioned on a generally horizontal surface.

[0037]FIG. 10 is a cross-sectional side view taken along line 10-10 of FIG. 9, illustrating a first preferred position of the abduction pommel relative to the incline block.

[0038]FIG. 11 is a cross-sectional side view similar to FIG. 10, illustrating a second preferred position of the abduction pommel relative to an elongated incline block.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] Referring now to the drawings, FIGS. 1-7 show a first preferred embodiment of the portable hip abduction apparatus, generally indicated at reference character 10. And FIGS. 8-11 show a second preferred embodiment of the portable hip abduction apparatus, generally indicated at reference character 10′. Generally, the hip abduction apparatus includes a flexible sheet 11, generally indicated at reference character 11, an abduction pommel 25 which functions to abduct the legs and hips of a user when straddle-seated on the flexible seat 11, and means for connecting (preferably releasably connecting) the abduction pommel 25 to the flexible sheet 11. Because of its essentially two or three piece, light-weight construction, the hip abduction apparatus 10, 10′ may be easily carried for use with virtually any seating arrangement encountered, including but not limited to chairs, benches, theater seats, or even a level surface such as the floor.

[0040]FIG. 1 shows a plan view of a first preferred embodiment of the hip abduction apparatus 10 when the flexible sheet 11 is laid out on a flat surface. Preferably, the flexible sheet 11 has a substantially rectangular-shaped layout, with a front edge 12, a back edge 13, and a pair of opposing side edges 14 which are substantially parallel to each other. However, the layout shape of the flexible sheet 11 is not limited only to such. The flexible sheet 11 is generally suitably dimensioned to enable proper and uninhibited operation of the hip abduction apparatus 10 according to the methods described herein. And it is appreciated that the term “flexible,” as used herein and in the claims, is defined to mean the ability of the sheet 11 to bend or conform to various seating surfaces and arrangements. While it is preferred that the flexible sheet be constructed from a non-stretch material, it is believed that some degree of stretching would not prevent proper operation of the apparatus 10.

[0041] For the first preferred embodiment of the apparatus 10, the flexible sheet 11 has three component sections: a pommel section 15, a back section 21, and a seating section 18 between the pommel section 15 and the back section 21. It is appreciated that the broken lines bordering each of the sections merely indicate the locations of the three sections relative to each other, and do not define the precise metes and bounds of the sections. Thus the sections are understood to extend to the pertinent edges of the flexible sheet 11, as well as to the border(s) shared with a neighboring section(s). And as shown in FIG. 2, each of the three component sections have a top surface and a bottom surface. In particular, the pommel section 15 has a top surface 16 and a bottom surface 17, the seating section 18 has a top surface 19 and a bottom surface 20, and the back section has a top surface 22 and a bottom surface 23. Each of the bottom surfaces 17, 20, 23 are friction-inducing surfaces which effectively restrain the sliding sheet 11 from sliding or slipping when positioned to contact a surface. Preferably, an elastomeric material having a high coefficient of friction, such as rubber, is utilized for the friction-inducing surface. It is appreciated that the bottom surfaces of the flexible sheet 11 may be adhere-coated with a layer of friction-inducing material. Alternatively, the flexible sheet 11 may be constructed in its entirety from a strong and durable friction-inducing material.

[0042] As shown in the figures, the portable hip abduction apparatus 10 also includes an abduction pommel 25 which operates to abduct or spread open the legs of a user when interpositioned therebetween. Generally, the abduction pommel 25 has a block configuration with an inner end 27, and an opposing outer end 26. Moreover, the abduction pommel 25 preferably has a trapezoid-shape block configuration where the inner end 27 and outer end 26 are parallel surfaces facing in opposite directions, and the outer end 26 is wider than the inner end 27. Thus, the abduction pommel 25 diverges from the inner end 27 to the outer end 26 at a predetermined angle of divergence. It is notable that the angle of divergence is not limited to any particular measure or range of measures. The selection of angle of divergence may depend on various use and application parameters, such as the age and height of an intended user, as well as the type of seat(s) for which the abduction apparatus 10 is to be used if known. For example, it is believed that an abduction apparatus 10 intended for use by an infant may have an abduction pommel with a wide angle of divergence due to the infants shorter legs. In contrast, an adult may not be able to achieve comparably wide divergence angles, especially when the apparatus is to be used primarily on seats having armrests or sidewalls. Generally, it may be appreciated that as the angle of divergence increases to produce greater hip abduction, the greater the rotation and tilt of the pelvis in the anterior direction towards neutral. It is notable that “neutral” and neutral position is defined as the pelvis to femur angle which is substantially vertical, i.e. ninety degrees.

[0043] As can be seen in FIGS. 1-4, the abduction pommel 25 is connected to the top surface 16 of the pommel section 15 of the flexible sheet 11 near the border shared between the pommel and seating sections, 15, 18 respectively. As can be seen, the divergence angle opens away from the seating section 18, i.e. the outer end 26 is spaced a greater distance from the seating section 18 than the inner end 27. Thus, where the abduction pommel 25 preferably has a trapezoid-shaped block configuration with the inner 27 and outer 26 ends being relatively flat surfaces, the outer end 26 generally faces a direction away from the seating section 18, and the inner face 27 generally faces in the direction of the seating section 18. Thus, when a user's buttocks are seated on the seating section 18 and the user's thighs are straddled around the abduction pommel 25, the diverging shape of the abduction pommel 25 provides ergonomic and symmetric abduction of the user's legs and hips. Furthermore, it is notable that the abduction pommel 25 preferably has a suitably semi-rigid foam construction which provides a suitable level of comfort to the user's pelvic region when the abduction pommel 25 is placed in supportive contact therewith.

[0044] Furthermore, the abduction pommel 25 is preferably releasably connected to the top surface 16 of the pommel section 15 of the flexible sheet 11. And preferably still, the abduction pommel is releasably connected using hook and loop material commonly marketed under the trademark Velcro. As shown in the figures, preferably a connector patch 24 of such material (e.g. loop material) is affixed to the top surface 16 of the pommel section 15. And although not shown in the figures, a corresponding connector patch (e.g. hook material) may be affixed to the underside of the abduction pommel 25. The abduction pommel's ability to be released and removed clear of the flexible sheet 11 allows a user to conveniently stand up from the flexible sheet 11 and exit a wheelchair or other seat without obstruction or interference. It is notable, however, that the abduction pommel 25 is preferably releasably attached to the flexible sheet 11 before the user straddle-sits thereon, in order to effect proper operation of the abduction apparatus 10 (see discussion below).

[0045] Alternatively, the abduction pommel 25 may be permanently attached and connected to the top surface 16 of the pommel section 15 of the flexible sheet 11. This would enable the component parts of the abduction apparatus 10 to effectively operate as a single unitary body. Furthermore, alternative methods of releasably or permanently attaching the pommel 25 to the flexible sheet 11 may also be utilized such as, for example, by employing a pocket affixed to the top surface 16 of the pommel section 15 for securely receiving the abduction pommel. In any case, the connection between the abduction pommel 25 and the flexible sheet 11 is such that the abduction pommel 25 is restrained from moving relative to the flexible sheet 11, and in particular from moving laterally along the top surface 16 of the flexible sheet 11.

[0046] As illustrated in FIGS. 3-5 and 7, the three-section construction of the first preferred embodiment hip abduction apparatus 10 may be placed on a seat 33 having a base 34 and a backrest 37. For illustrative purposes, a conventional chair 33 is used in the figures. However, it is contemplated that any type and style of seat having base and backrest portions may also be used. In FIGS. 3-5 and 7, the chair 33 has a base 34 with front 35 and rear 36 ends, and a backrest 37 with upper 39 and lower 38 ends. Further, the lower end 38 of the backrest 37 is connected to the rear end 36 of the base 34. It is appreciated that while the backrest 37 in FIGS. 4 and 5 is shown swept back a suitable angle such that a user may recline comfortably thereagainst, the presence of such recline angle is not necessary for proper operation of the hip abduction apparatus 10.

[0047] The flexible sheet 11 is positioned on the seat 33 with the pommel section 15 contacting the base 34 and the back section 21 contacting the backrest 37. In particular, the pommel section 15 is positioned near the front end 35 of the base 34, and the back section 21 is preferably positioned against substantially all of the backrest 37 from the upper end 39 to near the lower end 38. And the seating section 18 is positioned between the pommel 15 and back 21 sections adjacent the rear end 36 of the base 34 and the lower end 38 of the backrest 37. As can be seen in FIG. 5, the seating section 15 is preferably partially suspended above the seat 33 such that a gap space is produced therebetween adjacent the intersection of the base 34 and the backrest 37. This gap space helps to wedge a user between the abduction pommel 25 and the backrest, as will be discussed in detail below. It is notable that because of the preferably elongated and rectangular-shaped construction of the flexible sheet 11, the back edge 13 of the flexible sheet 11 may hang over the top end 39 of the backrest 37. Additionally, a supplementary attachment or hanging means may be provided at or near the back edge 13 of the flexible sheet 11 for releasably securing the back edge 13 to the top end 39 of the backrest 37. Such a feature may assist the friction-inducing bottom surfaces in restraining the flexible sheet 11 from slippage.

[0048]FIGS. 4 and 5 show a user 40 seated on the seat 33 to illustrate the operation of the hip abduction apparatus 10 to abduct the user's legs and hips. Upon positioning the hip abduction apparatus 10 on the seat 33 as described above, the user 40 may seat himself, or be seated by another, on the top surface 19 of the seating section 18 of the flexible sheet 11 to straddle the abduction pommel 25. The top surface 19 of the seating section 18, as used herein and in the claims, is that surface and section which is contacted by the user's buttocks when the user 40 is seated on the flexible sheet 11. And the user's thighs contact the top surface 16 of the pommel section 15 when in the straddled position, and the user's back contacts the top surface 22 of the back section 21 as well.

[0049] When the user 40 is seated thus, the user's weight is distributed against the top surfaces 16, 19, and 22 of the three sections 15, 18, and 21. This weight load distribution produces friction along the friction-inducing bottom surfaces 17, 20, and 23 of the respective sections to restrain the flexible sheet 11 from slipping or sliding relative to the contact surface. In particular, as shown in FIG. 5, a friction force F₁ is produced along the base 34, and a friction force F₂ is produced along the backrest 37, both in a direction opposite that of slip. Due to the friction, the flexible sheet 11 and the abduction pommel 25 may be held relatively stationary with respect to the seat 33 when the user is straddle-seated thereon. In this manner, the user's pelvic region may be lowered between the abduction pommel 25 and the backrest such that the user's pelvic region is caused to be wedged between the abduction pommel 25 and the backrest 37. It is notable that releasably-connecting abduction pommels should be in place and releasably connected to the flexible sheet 11 prior to the user sitting down, in order to ensure proper wedging action. When exiting the straddle-seated position, however, the releasably connectable abduction pommel may be removed first to allow a clear and unobstructed exit path.

[0050] While not being bound by any particular theory, it is believed that the dynamic wedging action of the user's pelvic region between the abduction pommel 25 and the backrest is largely due to (1) operation of an incline surface to redirect a user's weight in a forward direction, and (2) the proximity of the abduction pommel to the incline surface.

[0051] As shown in FIG. 5, the backrest 37 itself may function as an incline surface due to its partially reclined position typical of many chairs and seats. Thus a user 40 being seated will have his pelvic region approach progressively closer to the abduction pommel 25 the further down he slides toward the lower end 38 of the backrest 37. Moreover, the incline of the backrest 37 functions to urge the pelvis to rotate forward into the abduction pommel 25. Alternatively, as can also be seen in FIG. 5, the abduction apparatus 10 may be preferably positioned on the chair 33 with a substantial portion of the seating section 15 marginally raised above the chair 33 to form a curvilinear incline surface situated above a gap space. Similar to the reclined configuration of a backrest, the effect of this curvilinear incline surface is to urge the user's pelvic region forward toward the abduction pommel 25 and rotate the pelvis in forward in the anterior direction. At least in regards to the wedging action, it is appreciated that the curvilinear incline surface may be considered a constructive extension of the backrest 37 due to its physical dependency on the backrest 37.

[0052] Additionally, it is believed that the close proximity of the abduction pommel and backrest helps to produce the wedging action as well. As can be best seen in FIG. 1, the seating section 18 preferably has a width less than each of the widths of the pommel 15 and back 21 sections when viewed along the longitudinal axis of the flexible sheet 11. The relatively narrow width of the seating section 18 enables the abduction pommel 25 to be positioned in relatively close relation to the back section 21, and the backrest 37 of the seat 33 as well. Furthermore, it is notable that the width of the seating section 15 is preferably less than or equal to the front-to-back span of a user's pelvic region. In this manner, the abduction pommel 25 may firmly contact the pelvic region along with the backrest 37 to effect abduction and anterior rotation of the pelvis.

[0053] It is appreciated, therefore, that the wedging action may be characterized as the re-direction of a user's upper torso weight towards an abduction pommel 25 by means of a downward sloping incline surface. Moreover, this can be generally expressed as a wedging vector, illustrated in FIG. 5 as arrow W₁ directed between the abduction pommel 25 and the incline surface. Thus, when a user, such as a child 40, is seated, the child's seated weight is in effect re-directed in a slanted direction whereby the pelvic region is pressed against the abduction pommel 25. In this manner, operation of the hip abduction apparatus 10 causes the abduction pommel 25 situated between the legs of the user 40 to exert an abduction force against the inner thighs of the user 40 to induce hip abduction. Furthermore, the back section 21 of the flexible sheet 11 may be pulled upward while the user is seated, to draw the abduction pommel 25 closer to the backrest 37. This produces further rotation of the pelvis in an anterior direction toward neutral, for additional posture correction and support.

[0054] As shown in FIG. 6, the hip abduction apparatus 10 may further include an incline block 30 preferably formed from a semi-rigid foam material to provide cushioned support to the pelvic region. The incline block 28 has a lower surface 29 for contacting a seat surface, i.e. the base 34, and an incline surface 30 sloping up from a lower edge 31 to an upper edge 32 above the lower surface 29. The incline surface 30 may be suitably angled relative to the lower surface 29 to produce the wedging action discussed above. Furthermore, both the lower surface 29 and incline surface 20 of the incline block 30 are preferably friction-inducing surfaces which help to prevent the flexible sheet 11 from moving when a user is seated thereon.

[0055] In FIG. 7, a side elevational view is shown similar to that shown in FIG. 5 with the hip abduction apparatus 10 using the incline block 28 to assist in re-directing the user's seated weight towards the abduction pommel 25. The user's weight load distribution along the flexible sheet 11 produces friction along the friction-inducting bottom surfaces 17, 20, and 23 of the respective sections to restrain the flexible sheet 11 from slipping or sliding relative to the contact surface. The frictional forces produced along the base 34, the backrest 37, and the incline block 28 are represented by frictional forces F₃, F₅, and F₄, respectively. And the resulting wedging vector is indicated at reference character W₂. It is notable that the advantage of using an incline block where the seat 33 has both a base and a backrest 37, is that the gap space shown in FIG. 5 may be obviated. With the seating section 15 thus supported, the back section's 21 tendency to slide downward may be reduced, as well as the tension produced therein. Thus, the flexible sheet 11 and the abduction pommel 25 may be held relatively stationary with respect to the seat 33 when the user is straddle-seated thereon. And consequently, improved anterior rotation of the pelvis may result due to the direct inducement produced by the inclined seating section 15 against the user's buttocks.

[0056]FIG. 8 shows a plan view of a second preferred embodiment of the hip abduction apparatus, generally indicated at reference character 10′. Similar to the construction of the first preferred embodiment of the hip abduction apparatus shown in FIG. 1, the second preferred embodiment also includes a flexible sheet 11 preferably bounded by a front edge 12, a back edge 13, and parallel side edges 14. Unlike the first preferred embodiment, however, the second preferred embodiment utilizes only a pommel section 15 and a seating section 18. Each of the pommel and seating sections 15, 18 have a top surface and a bottom surface. In particular, the pommel 15 has a top surface 16 and a bottom surface 17, and the seating section 18 has a top surface 19 and a bottom surface 20. Furthermore, and similar to the first preferred embodiment, the second preferred embodiment also has an abduction pommel 25 preferably releasably connected to the top surface of the pommel section 15 by means of hook and loop material, shown as a pad 24 in FIG. 8.

[0057] As can be seen in FIGS. 9 and 10, the second preferred embodiment of the hip abduction apparatus 10′ utilizes the incline block 28 (discussed above) as a means for progressively elevating the seating section 18 as distance from the pommel section 15 increases. Because the second embodiment of the hip abduction apparatus 10′ is not utilized with a seat having a backrest, the incline block 28 alone functions to re-direct the user′s weight towards the abduction pommel 25 and rotate the pelvis in an anterior direction. This is accomplished by positioning the incline block 28 between the seating section 19 and the generally horizontal surface 41 such that the incline surface 30 of the incline block 28 contacts the friction-inducing bottom surface 20 of at least the seating section 19. Moreover, the incline block is oriented such that the upper edge 32 of the incline block 28 is spaced a greater distance from the pommel section 15 than the lower edge 31.

[0058]FIG. 10 shows one preferred position of the abduction pommel 25 relative to the incline block 28. As shown in FIG. 10, the incline block 28 may be positioned beneath the seating section 19 of the flexible sheet 11 such that the abduction pommel is juxtaposed adjacent to the lower edge 31 25. However, as shown in FIG. 11, the incline block 28 may alternatively support at least a portion of the pommel section 15 in addition to the seating section 18. Therefore, the abduction pommel 25 may effectively rest atop the incline surface 30 of the incline block 28 as well. In either case, the incline block 28 operates to redirect user's seated weight toward the abduction pommel 25, and is characterized by the wedging vectors W₃ in FIG. 10 and W₄ in FIG. 11. And similar to the first preferred embodiment, the wedging effect produced in this manner causes the abduction pommel 25 to exert an abduction force against the inner thighs of the user to induce hip abduction and anterior rotation of the pelvis.

[0059] It is notable that while the present discussion is primarily focused on patients with cerebral palsy and the particular pathological motor control traits associated therewith, it is not limited only to such. The claims are directed to the physical treatment of any individual deficient in motor control and/or motor function such that they require some form of stabilization when in a seated position. It is intended that this group include those whose musculatory and motor dysfunctions are caused by injury, genetic disorder, disease, illness, etc. However, the posture-correcting benefits of such an apparatus may be realized by healthy inviduals as well. It is also notable that the apparatus may be utilized for a variety of age groups, including infants, young children, as well as adults. Thus the apparatus may be manufactured in various sizes and dimensions as well as customized to suit specific needs.

[0060] The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive; the scope of the invention being indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein. 

I claim:
 1. A portable hip abduction apparatus for improving the posture of a user, especially a user with cerebral palsy, when sitting on a seat having a base and a backrest, said apparatus comprising: a flexible sheet having a pommel section, a back section, and a seating section between the pommel section and the back section, each of the sections having a top surface and a friction-inducing bottom surface; an abduction pommel for abducting the legs and hips of a user; and means for connecting the abduction pommel to the top surface of the pommel section of the flexible sheet such that a user seated on the top surface of the seating section may straddle the abduction pommel, whereby, upon positioning the flexible sheet and abduction pommel on the seat such that the friction-inducing bottom surface of the pommel section contacts the base and the friction-inducing bottom surface of the back section contacts the backrest and upon subsequently straddle-seating a user on the flexible sheet to exert a distributed load against the top surfaces of the flexible sheet, the friction-inducing bottom surfaces of the flexible sheet restrain the flexible sheet from slipping on the seat such that the user is wedged between the abduction pommel and the backrest by the user's weight, and the wedging action causes the abduction pommel to abduct the user's hips and rotate the user's pelvis in an anterior direction toward neutral.
 2. The apparatus as in claim 1, wherein the means for connecting the abduction pommel to the top surface of the pommel section comprises means for releasably connecting the abduction pommel to the top surface of the pommel section.
 3. The apparatus as in claim 2, wherein the means for releasably connecting the abduction pommel to the top surface of the pommel section comprises hook and loop material.
 4. The apparatus as in claim 1, further comprising an incline block for progressively elevating the seating section of the flexible sheet as distance from the pommel section increases, said incline block having a lower surface for contacting the base of the seat, and an incline surface sloping upward above the lower surface from a lower edge to an upper edge, said incline surface for contacting the friction-inducing bottom surface of at least the seating section of the flexible sheet with the upper edge of the incline block spaced a greater distance from the pommel section than the lower edge, whereby the incline block contributes to the wedging action of the user between the abduction pommel and the backrest of the seat.
 5. The apparatus as in claim 4, wherein the lower surface of the incline block is a friction-inducing surface.
 6. The apparatus as in claim 1, wherein the abduction pommel has a semi-rigid foam construction for providing cushioned support to a user's pelvic region during hip abduction.
 7. A portable hip abduction apparatus for improving the posture of a user, especially a user with cerebral palsy, when sitting on a generally horizontal surface, said apparatus comprising: a flexible sheet having a pommel section and a seating section adjacent the pommel section, each of the sections having a top surface and a friction-inducing bottom surface; an abduction pommel for abducting the legs and hips of a user; means for connecting the abduction pommel to the top surface of the pommel section of the flexible sheet such that a user seated on the top surface of the seating section may straddle the abduction pommel; and an incline block for progressively elevating the seating section as distance from the pommel section increases, said incline block having a lower surface for contacting the generally horizontal surface, and an incline surface sloping upward above the lower surface from a lower edge to an upper edge, said incline surface for contacting the friction-inducing bottom surface of at least the seating section of the flexible sheet with the upper edge of the incline block spaced a greater distance from the pommel section than the lower edge, whereby, upon positioning the flexible sheet and abduction pommel on the generally horizontal surface with the incline block placed between the generally horizontal surface and at least the seating section of the flexible sheet and upon subsequently straddle-seating a user on the flexible sheet to exert a distributed load against the top surfaces of the flexible sheet, the friction-inducing bottom surfaces of the flexible sheet restrain the flexible sheet from slipping on the incline block such that the user is wedged between the abduction pommel and the incline block by the user's weight, and the wedging action causes the abduction pommel to abduct the user's hips and rotate the user's pelvis in an anterior direction toward neutral.
 8. The apparatus as in claim 7, wherein the means for connecting the abduction pommel to the top surface of the pommel section comprises means for releasably connecting the abduction pommel to the top surface of the pommel section.
 9. The apparatus as in claim 8, wherein the means for releasably connecting the abduction pommel to the top surface of the pommel section comprises hook and loop material.
 10. The apparatus as in claim 7, wherein the lower surface of the incline block is a friction-inducing surface.
 11. The apparatus as in claim 7, wherein the abduction pommel has a semi-rigid foam construction for providing cushioned support to a user's pelvic region during hip abduction.
 12. A method for abducting the hips of a user, especially a user with cerebral palsy, to improve the posture of the user when sitting on a seat with a base and a backrest, said method comprising the steps of: providing a hip abduction apparatus comprising a flexible sheet having a pommel section, a back section, and a seating section between the pommel section and the back section, each of the sections having a top surface and a friction-inducing bottom surface, and an abduction pommel for abducting the legs and hips of a user; connecting the abduction pommel to the top surface of the pommel section of the flexible sheet such that a user seated on the top surface of the seating section may straddle the abduction pommel; positioning the hip abduction apparatus on the seat with the friction-inducing bottom surface of the pommel section contacting the base and the friction-inducing bottom surface of the back section contacting the backrest; seating a user on the flexible sheet to straddle the abduction pommel and exert a distributed load against the top surfaces of the flexible sheet; restraining the flexible sheet from slipping on the seat by action of the friction-inducing bottom surfaces of at least the pommel and back sections; and wedging the user between the abduction pommel and the backrest by the user's weight such that the wedging action causes the abduction pommel to abduct the user's hips and rotate the user's pelvis in an anterior direction toward neutral.
 13. The method as in claim 12, further comprising the step of pulling up the back section of the flexible sheet while the user is seated, such that the abduction pommel is drawn closer to the backrest of the seat and the user's pelvis is further rotated in an anterior direction toward neutral.
 14. The method as in claim 12, wherein the step of positioning the hip abduction apparatus on the seat produces a gap space between the seating section and the seat, whereby the top surface of the seating section is an inclining surface for urging a seated user toward the abduction pommel and rotating the user's pelvis in an anterior direction toward neutral. 